The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Motor vehicles include various driver interface devices and systems that enable a driver to control the movement of the vehicle from one place to another. The driver interface devices receive inputs from the driver and generate outputs based on the driver inputs. Conventionally, the driver interface devices include an accelerator pedal, a brake pedal, a cruise control system, a steering wheel, and a transmission gear (or range) selector or shifter manipulated by the driver. Various vehicle operating parameters, such as vehicle speed and direction, are determined based on the driver inputs.
The vehicle systems include a powertrain system, a brake system, a steering system, and a suspension system. The powertrain system produces drive torque used to accelerate the vehicle in response to driver inputs to the accelerator pedal and the shifter, and typically includes an engine, a transmission, and a driveline. The engine combusts an air and fuel mixture to produce torque that is transmitted through the transmission at various gear ratios to the driveline, which drives one or more wheels of the vehicle. The brake system includes brakes coupled to the wheels that produce braking torque used to decelerate the vehicle to a stop in response to driver inputs to the brake pedal. The steering system includes a steering wheel and various components coupling the steering wheel to the wheels that enable a driver to navigate the vehicle along a desired course. The suspension system includes a system of springs, shock absorbers, and linkages that connect the vehicle to the wheels. The suspension system contributes to the vehicle's road holding or handling and braking for safe navigation and driving pleasure, and serves to isolate vehicle occupants from road noise, bumps, and vibrations.
Each vehicle system includes one or more actuators for moving or controlling various subsystems and/or components and thereby varying various vehicle operating parameters. For example, a throttle of the engine may control engine air flow and thereby control engine torque output. Clutches and hydraulic pistons may control transmission gear ratio. A master cylinder may control braking force. Control systems have been developed to control operation of the actuators. In some control systems, one or more control modules alone, or in combination, generate control signals that are used to control the operation of the actuators. The actuators operate in response to the control signals, which are based on actuator values. Through control of the actuators, control systems can control various vehicle operating characteristics such as vehicle responsiveness and feel, and vehicle fuel economy.